A copy of Worksheet 1 at the appropriate level for each pupil. Ask pupils to answer the question 'What is sewerage?'

Transcription

1 Waste Water Treatment 1. Fascinating Facts Aim: To introduce pupils to key facts about waste water Materials: A copy of Worksheet 1 at the appropriate level for each pupil String Method: Ask pupils to answer the question 'What is sewerage?' Hand out Worksheet 1 and read though with pupils Discuss the facts and use the string to demonstrate the diameters of the sewers The next step is to find out what happens to the waste water

2 Waste Water Treatment - Worksheet 1 Fascinating Facts? Sewage is anything which flows through a sewer including bath water, industrial waste and toilet waste Rain water from the roads, roofs and gardens is known as surface water.? The more clean water we use, the more dirty water we make.? From your home, the dirty water flushed down the toilet, wash hand basin and kitchen sink all goes down the foul drain. This drain takes the water to the public sewer which takes it to the waste water treatment works.? Waste water is treated by Scottish Water before it is returned to the environment.? Under every road and street there is a network of sewers, pipes and pumps that carry the waste water away.? Sewers var y from 150mm (6") diameter leaving the house to 2400mm (96 ") for large city trunk sewers.

3 Savinter Waste Water Treatment - Worksheet 1 Fascinating Facts F Sewage is anything which flows through a sewer including bath water, industrial waste and toilet waste. Rain water from the roads, roofs and gardens is known as surface water. F The more clean water we use, the more dirty water we produce. F So that the natural environment can be protected and to control the possible spread of waterborne diseases, waste water is treated by Scottish Water before it is returned to the environment. F From your home, the dirty water flushed down the toilet, wash hand basin and kitchen sink all goes into the drain. This drain carries the water through to the public sewer which takes it to the waste water treatment works. F Underneath every road and street there is a network of sewers, pipes and pumps that carr y waste water to where it can be treated and returned to the environment. F Sewers var y in diameter from 150mm (6") leaving a house to the 2400mm (96") of large city trunk sewers.

4 Waste Water Treatment 2. How is waste water treated? 3. What happens to the water we use? Aims: To introduce pupils to the process of waste water treatment To enable pupils to become familiar with the process and relate it to their own community Material: A copy of Worksheet 2 and 3 at the appropriate level for each pupil Method: All the waste water that we produce is treated so that we can use it again Relate the discussion to the water cycle and the constant need for fresh water Hand out Worksheet 2 at the appropriate level and discuss the process Worksheet 3 provides more detail and can be used as an additional source of information Ask pupils to look around the school building or their home to find where waste water is removed

5 Waste Water Treatment - Worksheet 2 How is waste water treated? 1. Preliminary Treatment Screens trap solid items like rags, pieces of wood, paper and other debris. Grit and sand are removed. 2. Primary Treatment Waste water flows into tanks where solids sink to the bottom leaving a solid free liquid which is passed onto the next stage. 3. Secondary Treatment In secondary treatment a biological process is used. The bacteria consume the organic matter leaving the water clean. The resulting water is clean enough to be returned to the river or sea. In some works additional treatment is carried out to remove phosphates and ammonia. The solid material left by the treatment process is known as sludge. The sludge from the treatment process can be treated by de-watering or sludge digestion and recycled to agricultural land or forestry as a fertiliser and soil conditioner. Where this is not practical de-watered sludge may be used for landfill.

6 Waste Water Treatment - Worksheet 2 How is waste water treated? Stage 1: Screens trap rubbish. Stage 2: The grit is removed. Stage 3: The water rests in tanks where any large bits of dirt sink to the bottom. Stage 4: Good bugs grow in the tanks. They eat up any dirt that may be left over Stage 5: The waste water is allowed to rest again and the left over bits sink to the bottom of the tank. The bits of dirt that sink to the bottom of the tank are called sludge. This can be treated and recycled to farmland as a fertiliser.

7 Waste Water Treatment - Worksheet 3 What happens to the water we use? When you use water you make it dirty. We call this waste water. Sometimes you will hear it called sewage. This is what happens: Waste water from our toilet, wash hand basin and kitchen sink all goes into underground pipes below the house. These pipes join up with pipes from other houses and with pipes from factories offices and pavements. All these pipes go into larger pipes called sewers. This is where the word sewage come from. The sewers take all the waste to the waste water treatment works. Even the waste water from toilets can be cleaned there. It goes through different stages. Stage 1: Screens trap rubbish like rags, bits of wood and plastic. Stage 2: The grit is removed so it doesn 't damage the machinery. 1 2 Stage 3: The water rests in these tanks where any solids in the water sink to the bottom. The solids make a slimy mud called sludge. The sludge is drawn off into other tanks to be treated and made harmless. It can be used to make the soil better for growing plants or for burning to make electricity. Stage 4: Good bugs (bacteria) grow in the tanks. They eat up any waste material which could harm plants and animals. 3 4 Stage 5: The water is allowed to rest again. Large stirrers gently mix the liquid and the left over bits sink to the bottom of the tank. 5 The treated waste water is returned to the environment.

8 Waste Water Treatment 4. The Waste Water Treatment Story 5. Word Search Aims: To review the waste water treatment process To highlight key vocabulary Materials: A copy of Worksheet 4/5 at the appropriate level for each pupil Method: Hand out the worksheet at the appropriate level to each pupil Explain the task and set a deadline for completion (this is an appropriate homework task) Review answers to check understanding of waste water treatment process Hand out Worksheet 5 for pupils to complete word search

9 Waste Water Treatment - Worksheet 4 Waste Water Treatment Story Use the list below to fill in the missing words to tell the waste water treatment story. bacteria toilet treated bottom environment factories sewers waste material pipes waste water rubbish tanks sludge liquid Waste water from our t, wash hand basin and kitchen sink all goes into underground p. These pipes join up with pipes from other houses and with pipes from f offices and pavements. All these pipes go into larger pipes called s. The sewers take all the w w to the waste water treatment works. Here screens trap r like rags, bits of wood and plastic. The water is piped to large t where any solids in the l sink to the bottom. The solids make a slimy mud called s. This is drawn off into other tanks to be t. B _ or good bugs grow in the tanks. They eat any w m that might harm plants and animals. Large stirrers gently mix the liquid and the left over 'bits' sink to the b of the tank. The treated waste water is then returned to the e.

10 Waste Water Treatment - Worksheet 4 Waste Water Treatment Story Use the list below to fill in the missing words to tell the waste water treatment story. tank sewers pipes sludge bad toilet treatment rubbish good waste material pipes piped bottom animals Waste water from our t, wash hand basin and kitchen sink all goes into underground p. These join other p from factories, offices and pavements. All these pipes go into larger pipes called s. The sewers take all the waste water to the waste water t works. At the waste water treatment works screens trap r like rags. The water is p to large tanks where any solid bits sink to the b. These solid bits make a slimy mud called s. This is moved to other tanks and made harmless. Good bugs or bacteria are put into the water. The g bugs eat any w m that might hurt plants and animals. Large stirrers push any left over bits to the bottom of the t. The water is then returned to the environment.

11 Saving Waste Water Treatment - Worksheet 5 Waste Water Treatment - Wordsearch w a s t e u x a b u g s w s t a s e w e r e s l u d g e r u b b i s h t r e a t e d waste water sewer bugs sludge treated rubbish

12 Waste Savin Water Treatment - Worksheet 5 Waste Water Treatment - Wordsearch t o i l e t w w s s i r m s b a d a k l b u g s v n h s w u a s r w z k n t t d t r e a t e d e r g g j z t x k a u y e o m q e g p i p e s o a o r u b b i s h d a n i m a l s n e b a c t e r i a y i toilet treated rubbish tank sludge bugs pipes water animals bacteria waste bad good

13 Waste Water Treatment 6. How can we make water clean again Aims: To experience part of the waste water treatment process To design an experiment to show how the first part of the waste water treatment process works Materials: A copy of Worksheet 6 at the appropriate level for each pupil/group A jam jar with a lid, a large spoon, earth, water for each group Method: Explain that pupils are going to conduct one experiment which shows part of the waste water treatment process Hand out a copy of Worksheet 6 at appropriate level to each pupil Discuss the experiment and decide how pupils will record any changes they see, every 15 minutes then prepare the recording methods Divide the pupils into small groups and do the first stage of the experiment together and make sure that each group puts their jar in a safe place The next day pupils do the experiment again and stir the contents of the jar Pupils write up their experiment Discuss their findings and relate to the waste water treatment process Set homework task for some pupils to design an experiment to illustrate stage 1 of the cleaning process Allow time for the class to try out some or all of these experiments

14 Saving Waste Water Treatment - Worksheet 6 How can we make water clean again? How to find out: 1. Put 2 spoonfuls of earth into a jam jar of water. 2. Put the lid on and shake the jar until the water looks dirty. 3. Leave the jam jar and look at it every 15 minutes throughout the day. (Do not shake the jar again) 4. Record what happens. What next? You will need: - jam jar with a lid - a large spoon - earth - water 1. Do the experiments all over again, but this time use your spoon to stir the top of the water very, very slowly. (Do not put your spoon too far into the water) 2. Stir for 5 minutes and record what happens. Make sure you stir very slowly. Write a short report about your experiment. Try to answer these questions: 1. What did the first experiment achieve? 2. What did the second experiment achieve? What was different about the result? 3. Which stage of the waste water treatment process is each experiment most like? 4. Why do you think stirrers are used later on in the waste water treatment process? Other things to do: Look at the diagram of the waste water treatment process. See if you can design an experiment to show how stage 1 of the cleaning process works.

15 Saving Waste Water Treatment - Worksheet 6 How can we make water clean again? How to find out: 1. Put 2 spoonfuls of earth into a jam jar of water. 2. Put the lid on and shake the jar until the water looks dirty. 3. Leave the jam jar and look at it every 15 minutes throughout the day. (Do not shake the jar again) 4. Describe what you see each time you look at the jar. You will need: - jam jar with a lid - a large spoon - earth - water - timer What next? 1. Do the experiment all over again. This time use your spoon to stir the top of the water very, very slowly. Do not put your spoon too far into the water. 2. Turn the timer to 5 minutes and stir the water. 3. Describe what happens. Try to answer these questions: 1. What happened to the earth in the first experiment? 2. What was different about the second experiment? 3. Which stage of the waste water treatment process is each experiment most like? 4. Why do you think stirrers are used later on in the waste water treatment process?

16 Waste Water Treatment 7. Putting our used water back into the environment Aims: To demonstrate the interrupted water cycle To enable pupils to relate the waste water treatment process to the water cycle Materials: Copy of worksheet 7 for each pupil, plain paper, scissors and glue Method: Revise the water cycle explaining how water is taken out of the cycle and used for different purposes e.g. drinking, cooking, washing etc Hand out worksheet 7 and discuss the task Ask pupils to have their answers checked by another pupil before they glue the pictures in order (this is a suitable homework activity)

17 Saving Waste Water Treatment - Worksheet 7 Putting our used water back into the environment The Water Cycle gives us a constant supply of wate r. We take water from the cycle and use it for lots of different purposes. After we have used it, we clean our waste water and return it to the environment where it becomes part of the whole Water Cycle once again. If we returned our waste water without cleaning it, water pollution could cause animals and plants to die. Look at the pictures below. Each one shows a part of the Water Cycle. What to do: 1. Cut the pictures out and put them in order to show how we take water out of the water cycle, use it and put it back into the cycle. 2. Once you are sure you have the right order, glue them down to make a Water Cycle diagram. Draw arrows to show how the water moves around in the cycle. 3. Write a label for each picture.

18 Waste Water Treatment 8a/8b Waste Water Treatment Quiz Aim: To check pupils knowledge and understanding of waste water treatment Materials: A copy of Worksheet 8a for each pupil Method: Hand out Worksheet 8a for each pupil Set time limit Review answers with the whole class

19 Saving Waste Water Treatment - Worksheet 8a Waste Water Treatment Quiz True or False? Are the following statements True or False? Circle the answer. 1. There are five stages in the waste water treatment. True False 2. Waste water flows into tanks and the solid material floats to the top. True False 3. The waste water is left in these tanks to rest before the next part of the process. True False 4. Good bugs (bacteria), grow in the tanks. They eat any waste material which could harm plants or animals. True False 5. The particles of dirt that settle at the bottom of the tank are called sludge. True False 6. The water is now clean enough to be returned to the rivers or the sea. True False

20 Saving Waste Water Treatment - Worksheet 8b Waste Water Treatment Quiz Answer Sheet 1. True. They are called - preliminar y, primar y and secondar y. 2. False. The solid material sinks to the bottom leaving a liquid at the top. There still may be very small solids in this liquid. 3. True. 4. True. Good bugs eat the waste material. They just need the right level of oxygen to work. Too much and they don't work properly! 5. True. 6. True.